It is commonly known and practiced within this field of art that detachable, plastic bottle caps be mounted on the neck of standard five gallon bottles. Such bottle caps seal the bottle and the contents inside prior to the bottle's installation in a dispensing system. Normally, through the use of an attached pull tab and scoreline, the bottle cap is removed from its associated bottle prior to the bottle's installation and use. Examples of such caps are shown in the following U.S. Pat. Nos. 5,392,939; 5,370,270; 5,295,518; 4,991,635 and 4,699,188.
Recent developments in the bottle cap industry include a cap which has a central tube section which is capable of receiving a specialized dispensing probe from a dispensing system. This tube section has an inner seal which prevents the liquid from escaping the bottle until such dispensing probe is inserted. With this type of arrangement, the bottle cap itself need not be removed prior to its installation into a dispensing system.
While these newer types of bottle caps do, indeed, have liquid-tight seals, the surface areas of the bottle cap face and central tube section remain susceptible to external contaminants. Some manufacturers have addressed this concern by simply placing an adhesive-backed label upon the face of the bottle cap. This attempt to prevent contamination has at least one major drawback in that the labels, once removed, can again be reattached to the face of the bottle cap. If this is done carefully, there is no evidence that the label has been tampered with.
Alternatively, users of these systems have found it convenient to simply slap these labels on the side of the bottle rather than disposing of them in a waste container. This has two disadvantages. First, its is unsightly for such litter in the form of a used label to appear on the bottle when it is inverted on to a dispenser. Second, bottlers are forced to perform the step of removing the label from the side of the bottle before reusing the bottle. The adhesives used on such labels made this task quite difficult and costly.
Another problem which sometimes arises with valved or otherwise openable bottle caps is that they occasionally, although rarely, leak. Five gallon bottles are usually shipped in the horizontal position, which puts substantial hydraulic pressure on the cap and the particular seal associated therewith. Leaks may occur because of a small defect in the seal between components of the cap, or because of assembly problems. Pressure sensitive labels currently used in the industry over the top of valved or otherwise openable caps are not effective to provide even a secondary liquid-tight seal.
In light of the safety deficiencies and additional burdens associated with the protective labels which currently exist, what is still needed in this field of art is a tamper-evident label which can be easily and inexpensively attached to a standard bottle cap, which provides a liquid-tight seal and which cannot be reattached to the cap, or any other surface, once it is removed.